1. Field of the Invention
This invention relates to a multicolor ribbon assembly for use with a printing mechanism. More particularly, this invention relates to a multicolor ribbon cassette system for use with a matrix printer.
2. Prior Art
In most types of printing mechanisms, ranging from simple typewriters to complex printers, ribbon shifting is accomplished by holding a section of the ribbon in a pivoting bail arm which moves the ribbon up or down to align the correct color band with the printing mechanism such as a print head. The bail arm supports the ribbon in an operating plane which is parallel to a printing medium. One particular arrangement, which is directed to a ribbon cassette with bi-color-capability, is disclosed in U.S. Pat. No. 4,088,218 to Depew. This system, which is specifically designed for use with a matrix print head, includes a body portion having a chamber for storing a ribbon. The ribbon passes around an extension which is pivotal to move the ribbon either up or down with respect to its position within the cassette.
Although a pivotal bail arm is generally satisfactory when only two colors are to be employed, excessive vertical movement of the ribbon can cause snagging and dragging, especially when the ribbon is carried within a cassette. Therefore, it is a primary object of the present invention to provide a ribbon cassette system which provides smooth operation and enables more than two colors to be easily utilized. It is a further object of the present invention to provide a ribbon shifting mechanism which is simple and straightforward. Another object of the present invention is to provide a mechanism which can determine whether or not a cassette is in position and what type of cassette is being used.